The Heart Rate of Small Birds

Abstract

By use of a cardio-vibrometer which involves detection, amplification, and recording by a piezo-electric system, the basal heart rates were detd. for several spp. of common wild birds and also the canary. Basal conditions implied birds at rest, in a post-absorptive state, in darkness, at 30-32[degree]C, and away from human presence. In general, the smaller the sp. the faster the rate. Wild birds showed a seasonal difference in rate. Sex had no effect except in the domestic fowl. Marked lowering of rate caused sinus arrhythmia. The rate was an index of metabolic rate in regard to temp. effects. At low temps. respiratory rate was usually directly correlated with heart rate but this was reversed at high temps. The ratio of respiratory rate to heart rate was at least 1:6.